Reinforced replaceable tooth for digging machines



Oct. 11, 1966 LAUNDER EI'AL 3,277,592

REINFORCED REPLACEABLE TOOTH FOR DIGGING MACHINES Filed Sept. 17, 1963 2Sheets-Sheet 1 INVENTORS L, LAO/V052 //V/E Z. 440N058 BY 7 Oct. 11, 1966R. L. LAUNDER ETAL 3,277,592

REINFORCED REPLACEABLE TOOTH FOR DIGGING MACHINES Filed Sept. 17, 1963 2Sheets-Sheet 2 INVENTORS' E/CH/LQD A- LAUA/DEE E/Q/V/E L. Z/JU/VDE/Q1.1% AWOEA/Ey United States Patent 3,277,592 REINFORCED REPLACEABLETOOTH FOR DIGGING MACHINES Richard L. Launder and Ernie L. Launder, bothof P.O. Box 330, Whittier, Calif. Filed Sept. 17, 1963, Ser. No. 309,4514 Claims. (Cl. 37142) This invention relates to reinforced replaceableteeth for digging machines, particularly digging machines in which thedigging teeth are subjected to excessive loads and extreme abrasion,such as earth rippers and heavyduty, power shovels,

Included in the objects of this invention are:

First, to provide a replaceable digging tooth and a special reinforcingmeans which envelopes the tooth at its juncture with the tooth holder,so as to minimize stress concentrations in this region and minimizebreakage of the tooth holder, even under extreme conditions of use.

Second, to provide a reinforced, removable tooth wherein both the toothand its reinforcing means are reversible to that, for example, after apredetermined portion of the metal has been abraded from one side of thetooth and reinforcing, both may be readily reversed to permit wear ofthe upper side.

Third, to provide a reinforcement for removable digging teeth of thetype having a wedge-shaped socket which fits a wedge-shaped toothholder, wherein the reinforcement is in the form of a loop having highhoop strength which encircles the tooth at its juncture with the toothholder, to reinforce the tooth against force tending to spread andrupture the tooth socket.

With the above and other objects in view, as may appear hereinafter,reference is directed to the accompanying drawings in which:

FIG. 1 is a side view showing one form of the reinforced tooth mountedon an earth ripper shank, shown detached from the tractor to which it isattached when in use;

FIG. 2 is a fragmentary, enlarged view taken within circle 2 of FIG. 1,and showing the digging tooth and reinforcing member in section;

FIG. 3 is a fragmentary, perspective view showing the root end of thedigging tooth;

FIG. 4 is a perspective view of the reinforcing member;

FIG. 5 is a fragmentary, sectional view taken through 55 of FIG. 2;

FIG. 6 is a longitudinal, sectional view showing a modified form of thereinforced tooth attached to a tooth holder of the type used on powershovels, the holder being shown in elevation;

FIG. 7 is a partial top, partial sectional view thereof;

FIG. 8 is a perspective view of the modified reinforcing member.

Reference is first directed to FIGS. 1 through 5 wherein the reinforcedtooth is attached to an earth ripper shank 1. The shank 1 is installedin a tool holder carried by a tractor, and is disposed in an essentiallyvertical position. The shank 1 includes a forwardly directed, downwardlyinclined, lower end portion 2 which terminates in a tapered point 3.

The upper and lower surfaces 4 and 5 of the tapered point 3 converge ata relatively steep angle. In the region between the lower portion 2 andthe tapered point 3, the upper and lower surfaces 4 and 5 of the taperedpoint merge gradually into the forward and under surfaces of the shank1, as indicated by 6 in FIG. 2. The lateral sides 7 of the tapered point3 also converge, but at a lesser angle than the upper and lower surfaces4 and 5. At the root end of the tapered point 3 the shank 1 is provided3,277,592 Patented Oct. 11, 1966 with abutments 8. The abutments havefull fillets 9 to minimize stress concentrations.

Fitted on the tapered point 3 is a tooth 10 having a tapered socket 11,which conforms closely to the upper and lower surfaces 4 and 5 as wellas to the lateral sides 7 of the tapered point 3. The tooth 10 continuesfrom its socket 11 to form a digging point 12.

At its root end the tooth 10 forms a peripheral abutment 13. At itsupper and lower sides the tooth 10 is provided with lugs 14 whichconform to the upper and lower surfaces 4 and 5.

The tapered point 3 is provided with a transverse bore 15, and thelateral sides of the tooth 10 are provided with openings 16 whichregister with the bore 15, so that the openings and the bore may receivea retainer pin 17. The retainer pin 17 may be of the type shown inPatent No. 2,716,822, issued to Launder et al. Sept. 6, 1955, entitledDigger Tooth Mounting.

Abutments 8 and 13 confront each other, and are spaced apart so as toreceive a reinforcing ring 18 therebetween. The reinforcing ring 18 isrectangular and includes side portions 19, for bearing engagement withthe abutment 8 and end portions 20 which overlie the lugs 14, and arecapable of bearing engagement with the portions of the abutment 13disposed-outwardly from the lugs 14.

The tooth 10 may be installed on the shank 1 by first placing thereinforcing ring 18 over the lugs 14 for support thereby, and thenguiding the tooth 10 onto the tapered point 3 until the openings 16 arein sufficient registry with the transverse bore 15 that the retainer pin17 may be driven into place. In the course of use of the earth ripper,the tooth 10 is subjected to extreme loads in a downward direction orupward direction, as indicated by the arrow 21 in FIG. 2.

The reinforcing ring or loop 18 is formed of high strength steel withthe grain structure so oriented that its side portions 19 especiallyhave high tensile strength. As a consequence, the reinforcing loop 18engages the lugs 14 to restrain the tooth socket 11 from spreading dueto the forces indicated by the arrow 21.

Also, due to the fact that the upper and lower surfaces 4 and 5 of thetapered point 3 merge gradually into the corresponding surfaces of theshank 1, as indicated by 6 in FIG. 2, stress concentrations areeliminated. Consequently, the heavy loads imposed are transmitted to theshank 1 while minimizing any danger that the tapered point 3 might fail.

It is sometimes desirable to install a wear pad 22 on the upper side ofthe shank 1.- The pad is provided with an extension 23 fitting within asocket formed within the shank 1 and held by retainer pins 17. The pad22 affords wear protection for the upper side of the reinforcing ring 18and the adjacent end of the tooth 10.

Reference is now directed to FIGS. 6, 7, and 8. In this construction thereinforced replaceable tooth is shown attached to a tooth holder 24, ofthe type commonly used in connection with power shovels. However, themodified structure may be adapted to ripper shanks or to otherconventional digging implements.

The tooth holder 24 includes a tapered or wedge-shaped point 25 and isprovided with side abutments 26. The tooth 27 is essentially the same asthe tooth 10, in that it includes a socket 28 of wedge-shaped form tofit tightly on the tapered point 25. Extending from the socket portionof the tooth 27 is a digging tip 29.

The open side of the socket 28 is provided with a peripheral endabutment 30, and at the upper and lower sides the peripheral abutment 30is provided with lugs 31 which bear against the cor-responding surfacesof the tapered point 25. As in the first described structure, thetapered point 25 is provided with a transverse bore 15, and the tooth 27is provided with mating openings 16 and retainer pins 17.

Fitted around the tapered point 25, adjacent to and in engagement withthe peripheral end abutment 30, is a reinforcing ring or loop 32 havingthe side webs '33 of high tensile strength, and top and bottom wear pads34. The forward ends of the wear pads 34 overlie the lugs 31, andproject above and below the normal surfaces of the tooth 27. The wearpads 34 also extend rearwardly or toward the tooth holder 24, and theirextremities overlie and bear against the tapered upper and lowersurfaces of the tooth holder 24.

The modified reinforcing ring or loop '32 functions essentially in themanner of the first described reinforcing ring. In addition, the top andbottom wear pads 34 are designed to be abraded in use, as indicated bydotted line 35. This occurs simultaneously with the wearing of the tooth27, as indicated by dotted line 36. When such wear has occurred, boththe tooth 27 and the reinforcing ring 32 may be inverted.

It should be noted that under some conditions of use the wear occursprincipally on the underside, and in other conditions of use, such aswhen used as a ripper tooth, the wear may be principally on the upperside. In either case, the reinforcing ring 32 and tooth 27 may bereversed to prolong their useful life.

While particular embodiments of this invention have been shown anddescribed, it is not intended to limit the same to the exact details ofthe constructions set forth, and it embraces such changes,modifications, and equivalents of the parts and their formation andarrangement as come within the purview of the appended claims.

1(a) A digging tooth structure, comprising:

(b) a tooth holder having a tapered point;

(0) the upper and lower surfaces of said point merging gradually intothe corresponding surfaces of said tooth holder;

(d) a tooth having a socket for receiving said tapered point, andincluding upper and lower lugs extending from its root end andconforming to the upper and lower surfaces of said tapered point;

(e) and a reinforcing ring encircling said tooth holder beyond the rootend of said tooth and overlying said lugs.

2(a) A digging tooth structure, comprising:

(b) a tooth holder terminating in a tapered point;

(e) abutmen-ts at the sides of said tooth holder;

(d) a tooth having a socket for receiving said tapered point and formingat its root end a peripheral abutment;

(e) said tooth also having at its upper and lower sides, lugs extendingfrom said abutment and conforming to the upper and lower surfaces ofsaid tapered point;

(f) and a reinforcing member encircling said tapered point between saidabutments and overlying said lugs.

3(a) A digging structure, comprising:

(b) a tooth holder including converging upper and lower sides, andabutments at opposite lateral sides;

(c) a tooth having converging upper and lower sides joined by lateralsides to form the walls of a socket adapted to receive and enclose saidtooth holder, said lateral sides terminating in abutment end facesconfronting said tooth holder abutments;

(d) a reinforcing loop having tension-resisting side straps interposedbetween said abutments, and top and bottom straps overlying the root endof said tooth to resist spreading of said socket;

(e) and means for securing said tooth to said tooth holder.

4(a) A digging tooth structure, comprising:

(b) a tooth holder including converging upper and lower sides, andabutments at opposite lateral sides;

(c) a tooth having converging upper and lower sides joined by lateralsides to form the walls of a socket adapted to receive and enclose saidtooth holder, said lateral sides terminating in abutment end facesconfronting said tooth holder abutments;

(d) a reinforcing loop having tension-resisting side straps interposedbetween said abutments, and top and bottom pads overlying the root endof said tooth to resist spreading of said socket, said pads alsooverlying the top and bottom surfaces of said tooth holder and exposedto abrading wear, thereby to minimize wear on adjacent surfaces of saidtooth holder and the socket-forming portions of said tooth;

(e) and means for securing said tooth to said toot-h holder.

References fitted by the Examiner UNITED STATES PATENTS 854,838 5/1907Parsons 37-442 1,776,676 9/1930 Bauer 37-142 2,762,139 9/1956 Launder37142 2,940,192 6/ 1960 Lattner 32-142 3,079,710 3/ 1963 Larsen et al172-762 X ABRAHAM G. STONE, Primary Examiner. WILLIAM A. SMITH, III,Examiner.

